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I've built a GPU mining rig for mining altcoin cryptocurrencies (ethereum et al) and I'm having problems with what I believe is either my PSUs or my power distribution.
The Hardware:
- 2 x Raidmax Cobra RX-700ae 80+ Gold 700W PSUs
- 1 x Intel Celeron G3930 Kaby Lake CPU
- 1 x Crucial 4GB DDR4 RAM
- 1 x Biostar 250-BTC Motherboard
- 1 x 60GB SSD
- 6 x PCIe Powered Risers (with USB and SATA to 6 pin cables)
- 2 x AMD Radeon RX480s (one 4GB and one 8GB)
- 3 x AMD Radeon RX580s (all 4GB)
- Running Windows 10 with AMD's Crimson ReLive Beta for Blockchain Compute (patched)
The current power setup:
I've got one PSU feeding power to the motherboard and CPU along with the two lowest power consuming GPUs and one of the powered risers.
The remaining 2 GPUs along with 3 of the powered risers are being fed power by the second PSU.
PUs are using 6+2 pin cables. Powered risers are using SATA cables from the PSU connected SATA -> 6 pin adapters, which are then plugged into the riser boards.
The problem:
Although both PSUs are rated for 700W and are 80 Plus Gold certified, I can't seem to get the 5th GPU to work without causing problems. I've tried feeding the 5th GPU and riser board power from the 2nd PSU and from the 1st PSU and switching GPUs around a bit without any luck so far.
One of the PSUs will shut off, I'll get a BSOD (blue screen of death), or some other problem occurs. These generally happen when I start Claymore Miner and put the GPUs under load. Prior to that, the GPUs report fine. Which is why I believe this is a power issue somewhere.
Right now, with just the 4 GPUs I'm reading 720 watts being drawn from the wall on average (using an outlet meter) between the two PSUs. This is just under what one of these PSUs are rated for.
Does anyone have any suggestions on what exactly the problem could be or whether I need higher rated PSUs or another PSU or if this is another problem that I am unaware of entirely? Thanks!
EDIT:
Both PSUs are connected to the same power strip, meaning they should be sharing the same external ground.
PSU 1 is pulling about 405W and PSU 2 is pulling about 315W on average.
Hi Ramhound. I have two PSUs and I'm splitting the load between the two. One PSU is running Mobo/CPU, two of the lower power consuming GPUs (about 20w less than the other 3 on average), and two powered risers. The second PSU is running 3 GPUs and 3 powered risers. – Jacob R – 2017-11-29T21:52:02.540
715 watts combined load split between both PSUs. Which would mean each PSU is doing roughly 357.5W each. For a PSU that's rated for 700W one would think this is a reasonable load. I'm working on getting reading for each PSU individually but it's sounding like either these PSUs perform terribly or there's something else going on. – Jacob R – 2017-11-29T22:03:44.427
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@Ramhound That's not how power supply efficiency works; it's not a way to determine "real" output power. A power supply should be able to provide its rated output power and then efficiency can be used to calculate the input power required (and power loss to heat), e.g. 700W rated/out at 80% eff would pull 875W in, wasting 175W. This particular supply is actually around 88% efficient on an 700W load.
– Bob – 2017-11-29T22:36:59.697I wonder if you could be running into cross-load issues. Some PSUs aren't too happy about a high load on the 12V rails with nothing on the 3.3V/5V. – Bob – 2017-11-29T22:58:54.693